Development of methods to assess lake sturgeon populations in Lake Champlain

Duration

July 2016 - June 2020

Narrative

Lake sturgeon Acipenser fulvescens are widely distributed in freshwater systems throughout North America, occupying both lake and riverine habitats. Like other members of the sturgeon family, lake sturgeon are long lived, slow to mature, display intermittent spawning, have high fecundity and low natural mortality. Despite their low natural mortality, these life history characteristics make them especially vulnerable to overexploitation. Lake sturgeon populations have declined throughout the range of the species due to factors including habitat loss and overfishing, and are listed as extirpated, endangered, threatened, or of special concern in 12 states. The State of Vermont listed the species as endangered in 1975 due to low abundances in Lake Champlain. In the late 1800s and early 1900s a small commercial fishery for sturgeon existed Lake Champlain, however current numbers are unknown and likely represent a small fraction of the historic population. Since 1998, the Vermont Department of Fish and Wildlife (VTFW) has conducted sampling that has documented adult spawners, eggs, and larvae in the Winooski, Lamoille, and Missisquoi rivers. Spawning adults have not been documented in Otter Creek, a historic spawning tributary of Lake Champlain. Successful reproduction is occurring in multiple rivers in the lake, however an understanding of the current population status is lacking in the system. In this study, we plan to document adult and juvenile movements, identify suitable spawning and nursery habitat, investigate age structure, and develop a method to estimate the population of lake sturgeon in Lake Champlain.